It is known to form polyketones by the polymerization of carbon monoxide and one or more olefins by a vapor phase polymerization process. For example, U.S. Pat. No. 4,778,876 of M. J. Doyle et al. describes such a process in which the monomers are contacted with the catalyst compositions in the substantial absence of a liquid, non-polymerizable diluent. Any small quantity of diluent that might be present is vaporized and present in exclusively the gaseous state during the polymerization (Col. 3, lines 35-40). This teaching of having any added alcohol diluent present exclusively or substantially in the gaseous condition during the polymerization reaction is substantially echoed by other, more recent patent references: European Patent Publication No. 248,483 (see Col. 3, lines 8-13 and Claim 2). European Patent Publication No. 443,587 (see Col. 3, lines 3-8 and Claim 2); and European Patent Publication No. 506,168 (see Col. 5, lines 29-35 and Claims 8-9).
Netherlands Patent Application No. 9101114, filed Jun. 27, 1991, and corresponding European Patent Publication No. 520,584 advocate a gas phase polymerization process for the manufacture of polyketones in which water is added to the polymerization reaction environment to enhance the polymerization activity of the polymerization process. The amount of water should range from more than one mole per gram atom of Group VIII metal in the catalyst, preferably more than 10 moles, for example, from about 5,000 to about 50,000 moles per mole of Group VIII metal. The upper limit of water added is set by the requirement that gas should form the continuous phase in the reactor. The European patent citation exemplifies the add-on of 1 ml and 7 ml water, respectively, to 8 g of porous carbon monoxide/ethene copolymer catalyst support. The present investigators have determined that a carbon monoxide/ethene copolymer becomes saturated at far higher levels of water add-on than 7 ml, namely, at about 40-43 g. The productivity using 7 ml of water (an add-on of about 88%) was inferior to that observed when a far lower add-on (14% for 1 ml of water) was employed.
In PCT International Patent Publication No. WO 93/25602 and related U.S. Pat. No. 5,331,083, a gas phase process for catalytically polymerizing carbon monoxide and at least one olefin to produce a polyketone is described. The particular improvement in the process of that particular invention was conducting the polymerization in the presence of a catalyst support which was substantially saturated with a liquid, non-polymerizable diluent which increased the amount of polyketone that was formed in the process. In one preferred embodiment of the process, a ketone, such as acetone, was used with the addition of hydrogen to yield a product of reduced molecular weight, increased bulk density, and increased thermal stability.
In the process shown in that patent publication, a quantity of catalyst was prepared and was dissolved in small amount of solvent forming a catalyst solution which was then sprayed onto a previously formed and isolated carbon monoxide/ethylene copolymer which had been wetted with a quantity of solvent (the "seed batch"). The polyketone-supported catalyst thereby produced was then placed into the reactor, the reactor was pressured with a mixture of carbon monoxide and olefin, such as ethylene, and stirring and heating of the reactor was begun to initiate the predominantly gas phase polymerization reaction.